[Serve][Part2] Migrate the tests to use deployment graph api

[sihanwang41]

Why are these changes needed?

Second pr for the test migration in the current session.

• ignore test_deployment_graph file since it is for testing internal deployment graph function, which need to use deploy() or list_deployment() etc to verify the correcness.
• ignore the test_fastapi and multi routes test with multi deployment which is not supported yet in the deployment graph.

Related issue number

Checks

• I've run scripts/format.sh to lint the changes in this PR.
• I've included any doc changes needed for https://docs.ray.io/en/master/.
• I've made sure the tests are passing. Note that there might be a few flaky tests, see the recent failures at https://flakey-tests.ray.io/
• Testing Strategy
  • Unit tests
  • Release tests
  • This PR is not tested :(

[edoakes]

@sihanwang41 there is a windows test failure in serve:test_gcs_failure. I don't see it failing on flaky test tracker. Re-ran it to see if it passes, but take a look?

[simon-mo]

@edoakes test_gcs_failure turns out hasn't been enabled in previous master builds. This PRs enables it. @sihanwang41 I think it's fine to skip it on windows if it is too hard to debug: https://github.com/ray-project/ray/blob/master/ci/ci.sh#L172

[sihanwang41]

In the test, we are using forked to isolate the environment. Looks like it is not supported in the windows.
code:

if __name__ == "__main__":
    # When GCS is down, right now some core worker members are not cleared
    # properly in ray.shutdown. Given that this is not hi-pri issue,
    # using --forked for isolation.
    sys.exit(pytest.main(["-v", "-s", "--forked", __file__]))

Exception ignored in: <function ForkedFunc.__del__ at 0x000001FE7FE99940>
Traceback (most recent call last):
  File "C:\Miniconda3\lib\site-packages\py\_process\forkedfunc.py", line 110, in __del__
    if self.pid is not None:  # only clean up in main process
AttributeError: 'ForkedFunc' object has no attribute 'pid'

I will skip the test on windows for now. @edoakes @simon-mo

[simon-mo]

//python/ray/serve:test_gcs_failure                                      FAILED in 3 out of 3 in 4.5s
--
  | Stats over 3 runs: max = 4.5s, min = 4.3s, avg = 4.4s, dev = 0.1s
  | C:/tmp/4lhdprva/execroot/com_github_ray_project_ray/bazel-out/x64_windows-opt/testlogs/python/ray/serve/test_gcs_failure/test.log
  | C:/tmp/4lhdprva/execroot/com_github_ray_project_ray/bazel-out/x64_windows-opt/testlogs/python/ray/serve/test_gcs_failure/test_attempts/attempt_1.log
  | C:/tmp/4lhdprva/execroot/com_github_ray_project_ray/bazel-out/x64_windows-opt/testlogs/python/ray/serve/test_gcs_failure/test_attempts/attempt_2.log

it still shows on windows. I think you have skip it on bazel target level. (see my previous comment)